1. Field of the Invention
The present invention relates to a system and method for controlling a start of a fuel cell vehicle, and more particularly, to a method for controlling a start of a fuel cell vehicle that ensures rapid startability by adjusting the amplitude of current output from a fuel cell to be at an allowable level while constant-voltage controlling the fuel cell upon the cold start of the fuel cell.
2. Description of the Related Art
Generally, driving of a fuel cell with a low voltage and a high current during a cold start is advantageous in that a fuel cell is heated. In other words, when the voltage of a fuel cell is adjusted to be a lowest voltage allowed by a system in an identical output condition, the fuel cell may be heated rapidly while outputting the highest current. A fuel cell, a converter configured to convert the voltage of a high-voltage battery, and an inverter configured to drive a motor in an actual fuel cell vehicle system are connected to each other at a high voltage bus, and the converter is constant-voltage-adjusted to a lowest allowable value during a cold start to maintain the voltage of the fuel cell low and to induce rapid heating.
In particular, in such a process, when a high-voltage battery is charged to supply current, the current output of the fuel cell may be increased to enable more rapid heating. Typically, the high-voltage battery is managed to be charged and discharged within the charge and discharge output limitation by operating a fuel cell and the converter with reference to charge output limitation (kW) and discharge output limitation (kW) information, generated by a battery management system (BMS).
As described above, since charging a battery with as much energy as possible during constant-voltage operation is a method that uses a substantial amount of output of the fuel cell, it is advantageous from the aspect of heating. However, charging may not be performed to the charge output limitation, or overcharging may occur, due to a current sensing error that occurs in a sensor configured to detect the angle between a charge current provided from a converter, which converts the output of the fuel cell to provide the converted output to the high-voltage battery, and a high-voltage battery current detected by the BMS in the high-voltage battery. Accordingly, even when there is sufficient energy to increase the charge current within a current limitation range, it is typically unfavorable to secure a heating amount for low-temperature heating of a fuel cell, or the durability of the high-voltage battery may be degraded due to overcurrent because a charge current is set low.
The matters described as the background arts are merely intended to increase the understanding of the background of the present invention, and should not be recognized as being prior arts which are already known to those skilled in the art.